FZJ80, with a wife and three children 9-14. Fitting everything in is a struggle, but we have it down to a science that works for us.
#1, rear bumper carrier can hold 20 gallons of water. I don't have to carry water in the truck.
#2, Yakima skybox. It is a big one and hold all the sleeping pads, sleeping bags, lightweight nylon tarps and pillows.
We couldn't do it easily otherwise without those two things. That means all that is in the rear of the Land Cruiser is the cooler, action packer chuckbox, food, recovery gear/tools, daypacks, table, chairs, tent, awning, clothes bags, etc. After I strap everything down I can still use the rear view mirror without trouble. We can do 5 days unsupported right now. That 5th day better be short though. Water is usually our limiting factor.
It can be done, just start approaching car camping like backpacking and you'll be surprised at what you can do without. We use coleman canisters and not a large LP tank. No lanterns, just headlamps. Two pairs of shoes, hiking boots or flipflob/keens. Be smart about food. We usually prepare and freeze a couple of meals. Reduced the amount of ice needed in the cooler. While I would love a fridge, the volume they carry vs footprint might cause us trouble compared to a good ice chest. Since we have a bit a room to spare, it may be a wash and a moot point. I will say the key for us was getting the water out of the truck and a good storage spot for the light stuff on the roof. Without the Yamima Skybox we could do it, but packed to the roof.
The good news is there are a thousand right answers, you just need to find a way to minimize both the quantity and size of the stuff you bring in way that still works for you. Creative packing works to. It is amazing all the nooks and crannies that will hold a shoe.
Now that the youngest is getting bigger, I want to utilize one of the rear seats so everyone has more room. Sadly, that means a trailer for us. I'm not interested in putting more on the roof. The bonus of a trailer is we can start bringing our mountain bikes and more water. That means more time away from civilization. :jumping:
GeoRoss took the words right out of my mouth. I was an backpacker before my wife and kids came along, and having that experience made all the difference. Check out some of the ultra-light backpacking forums for ideas packing light and small.